Electrochemically etched pores and wires on smooth and textured GaAs surfaces

The electrochemical etching behaviors of GaAs on smooth and textured surfaces were systematically investigated in aqueous KOH electrolytes. When the applied potential was higher than the pore formation potential (PFP), the electrochemical etching of the smooth surface could be categorized into three regions: pore/wire formation, texturing, and electropolishing regions. Triangular GaAs nanowires were observed at low potentials while pronounced lateral etching occurred at high potentials. In the case of the textured surface, which consisted of groove arrays, more complicated etching behavior was demonstrated. The pore growth direction changed from B to at a high current density while accompanying a drastic change in the pore morphologies such as tetrahedron-like pores along (1 1 1)B transforming into 200 mu m deep pores propagated along the direction. (C) 2011 Elsevier Ltd. All rights reserved.This work was supported by the Pioneer Research Center Program (No. 2010-0002231) and Nano R&D Program (No. 20090083229) through the National Research Foundation (NRF) grant funded by the Ministry of Education, Science and Technology (MEST). This work was supported by the New & Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea Government Ministry of Knowledge Economy (No. 2009T100100614). H.-D.Um acknowledges the financial support of the fifth-stage Brain Korea 21 Project in 2010